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<table width="100%" summary="page for kyphosis"><tr><td>kyphosis</td><td align="right">R Documentation</td></tr></table>

<h2>Data on Children who have had Corrective Spinal Surgery</h2>

<h3>Description</h3>


<p>The <code>kyphosis</code> data frame has 81 rows and 4 columns.
representing data on children who have had corrective spinal surgery
</p>


<h3>Usage</h3>

<pre>
kyphosis
</pre>


<h3>Format</h3>


<p>This data frame contains the following columns:
</p>

<dl>
<dt><code>Kyphosis</code></dt><dd>
<p>a factor with levels
<code>absent</code> 
<code>present</code>
indicating if a kyphosis (a type of deformation)
was present after the operation.
</p>
</dd>
<dt><code>Age</code></dt><dd>
<p>in months
</p>
</dd>
<dt><code>Number</code></dt><dd>
<p>the number of vertebrae involved 
</p>
</dd>
<dt><code>Start</code></dt><dd>
<p>the number of the first (topmost) vertebra operated on.
</p>
</dd>
</dl>


<h3>Source</h3>


<p>John M. Chambers and Trevor J. Hastie eds. (1992)
<EM>Statistical Models in S</EM>, Wadsworth and Brooks/Cole,
Pacific Grove, CA.
</p>


<h3>Examples</h3>

<pre>
fit &lt;- rpart(Kyphosis ~ Age + Number + Start, data = kyphosis)
fit2 &lt;- rpart(Kyphosis ~ Age + Number + Start, data = kyphosis,
              parms = list(prior = c(0.65, 0.35), split = "information"))
fit3 &lt;- rpart(Kyphosis ~ Age + Number + Start, data=kyphosis,
              control = rpart.control(cp = 0.05))
par(mfrow = c(1,2), xpd = TRUE)
plot(fit)
text(fit, use.n = TRUE)
plot(fit2)
text(fit2, use.n = TRUE)
</pre>


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